Steam-engine.



E. H. LUDEMAN.

STEAM ENGINE.

APPLICATION FILED JUNE 17, I915- Patented June 27, 1916.

2 SHEETS-SHEET I- THE COLUMBIA I'LANOGRAPH co., WASHINGTON, n. C.

E. H. LUDEMAN.

.STEAM ENGINE.

APPLICATION msn JUNE 11. 1915.

Patented June 27, 1916.

2 SHEETS-SHEET 2.

EDWIN H. LUDEMAN, OF BROOKLIZ'N, NEW YORK.

STEAM-ENGIN E.

Specification of Letters Patent.

Patented June 2'7, 191%.

Application filed June 17, 1915. Serial No. 34,640.

To all whom it may concern:

Be it known that I, EDWIN H. LUDEMAN, a citizen of the United States, residing at Brooklyn, in the county of Kings and State of New York, have invented certain new and useful Improvements in Steam-Engines, of which the following is a specification.

This invention'relates to improvements in steam engines of the type known as the unaflow engine, wherein the steam in its passage from the inlet port through the cylinder flows in but one direction, and is exhausted through ports at the middle of the cylinder which are uncovered by the piston at or near the end of the working stroke, or where the steam is admitted at the middle of the cylinder and exhausted at the ends of the cylinder through ports in the cylinder wall uncovered by pistons at or near the end of the working stroke.

Heretofore, unaflow engines have been built for either condensing or noncondensing operation. I11 other words, these en-. gines have been built to run either condensing or noncondensing at different times, but they cannot operate condensing and noncondensing at the same time.

The object of this improvement in unaflow steam engines is to allow the engine first to exhaust the steam into a heating system or atmosphere, and immediately thereafter to allow the residual steam in the cylinder and in the exhaust ports surrounding the cylinder to be exhausted into a condenser, which will have the eifect of obtaining approximately the economy of a condensing unaflow engine, with the advantage of being able to use a considerable portion of the exhaust steam for heating or other purposes requiring steam at moderately low pressures.

It has the further advantage of allowing the use of a smaller condenser than would be required by a unaflow engine from the cylinder of which all the steam exhausted were condensed.

This invention can also be applied tothe use of exhaust steam at two different-pressures when operating'noncondensing only. As an example: The steam could first be exhausted into a heating system, orinto a system using steam at a few pounds pressure above atmosphere; and immediately thereafter the residual steam in the cylinder could be exhausted into the atmosphere, thereby relieving the back pressure, due to exhaust into heating system, from the cylinder on the return orcompression stroke of the piston, and, by the relieving of this back pressure, of course increasing the economy as well as the power of the engine.

In the accompanying drawings, Figure 1 is a cross section of a cylinder provided with the invention. Figs. 2 and 3 are indicator diagrams. Figs. 4 and 6 are cross sections of modifications. Fig. 5 is a partial longitudinal section of Fig. 1.

Fig. l is a transverse cross-section of a unafiow cylinder having exhaust ports T located at the middle of the cylinder, the cross-section being taken through the ex haust belt or chamber R and at the middle of the cylinder; in which A is an exhaust valve located in the exhaust belt of the unaflow cylinder, controlling communication to the high pressure exhaust chamber B, which is. connected to the high pressure exhaust going to heating system or to other appliances requiring steam. The valve A is operated by a valve gear attached to a moving part of the engine, preferably the shaft, and, as shown, is merely a rod C on which are mounted cams D and D. Other means for operating this valve be employed, such as other designs of valve-gear; or the valve may be operated automatically.

E is another exhaust valve located in the exhaust belt of the unafiow cylinder, controlling communication to the low pressure exhaust chamber F, which in turn is connected to a condenser or to atmosphere or to a system of steam using appliances of lower pressure than that to which the exhaust chamber B is connected; or, in case it is desirable, it may be connected to asystem oi the same pressure as that to which chamber B is connected.

Valve E is shown to be operated by the rod C on which is mounted cam D, the rod C being actuated by a valve-gear connected to some moving part of the engine, preferably the shaft, although other means for operating this valve may be employed, such as other designs of valve-gear; or the valve may be operated automatically.

Springs G and G are used merely for allowing the valves A and E, respectively, to seat after they have been raised by cams D and D after said cams have been operated so as to release the pressure under the valve stems H and H; and other means of provid ing for seating of valves may be used.

The operation is substantially as follows: On the expansion stroke, the valve A is opened at or about the time the piston uncovers the exhaust ports in the cylinder, the steam flowing into the chamber B and thence to heating system or device using exhaust steam. At or about the end of this stroke, the valve A closes, and valve E opens allowing communication with chamber F for the residual steam left in the cylinder. If the chamber F is in communication with a condenser, a vacuum is formed in the exhaust belt and in that part of the cylinder from which the steam has just been exhausted; and, on the return stroke of the piston, a considerable back pressure has therefore been removed from the piston during the compression stroke by the vacuum in this end of the cylinder.

If it is desired to connect the chamber B to a system requiring steam of a certain pressure above atmosphere, and to connect chamber F to a system requiring a lower pressure than that of the system to which chamber B is connected (which pressure, however, is not below atmospheric pressure), the method of operation is the same as above described, the only exception being that there is no vacuum in chamber F and therefore in the cylinder of the unaflow engine. In this event, as soon as the valve A is closed and valve E is opened, the back pressure due to the system to which chamber 13 is connected is relieved, and the remaining pressure in the cylinder is relieved by the resid ual steam flowing through open valve E, so that the pressure in that end of the cylinder from which exhaust has just taken place is that of the pressure due to the system which is connected to chamber F.

Figs. 2 and 3 show approximately the indicator diagrams which would be obtained from a unaflow cylinder equipped with my improvement; Fig. 2 being a condensing diagram, and Fig. 3 being a noncondensing diagram. At point 1 and 1 the piston has uncovered the central exhaust ports in the walls of the cylinder, and exhaust is being effected through the open valve A to the high pressure system. The piston continues this movement toward the end of its stroke and farther across the exhaust ports until the end of the stroke is reached at points 2 and 2. Preferably at this point the exhaust valve A closes, and the exhaust valve E opens so that on the return stroke of the piston the residual steam is exhausted through open valve E to the low pressure exhaust which, as above stated, may be either an exhaust leading to a condenser or an exhaust leading to a system of lower pressure than that of the system connected to the chamber B; or it may lead if required, to a system having the same pressure as chamber B. The piston closes the exhaust ports in the cylinder at points 3' and 3 and that part of the cylinder from which the steam has just been exhausted has at this point of closure substantially the same pressure as is obtaining in chamber F.

Valve E closes preferably after the piston has closed the exhaust ports in the cylinder, and will remain closed until the cycle is repeated by the piston uncovering the exhaust ports when exhausting steam from the other end of the cylinder, if the engine is doubleacting, or by the piston returning on the next expansion stroke and opening the same end of the cylinder to the exhaust belt if the engine is single-acting. Valve A also remains closed until the cycle is repeated, as above set forth, said valve A opening before valve E and closing before or at about the same time valve E is opened.

Fig. 4 shows a modification of my device, in that a single valve I is employed. This valve has ports J and J which allow communication, as desired, between the unaflow cylinder and the chamber K connected to high pressure exhaust and the chamber L connected to low pressure exhaust. This valve I is operated by a valve-gear connected to some moving part of the engine, or it may be arranged to operate automatically. The

operation is as follows: Atabout the time 1 the piston of the expansion stroke uncovers the exhaust ports in the unaflow cylinder, the valve I opens (by moving to the right),

bringing its ports J in register with ports in cylinder casting M. At the same time, the ports J J are not in register with ports M M M M. Therefore, the exhaust takes place to the chamber K connected to high pressure system. Afterward, and before the piston has covered the exhaust ports in the cylinder on the return stroke, the valve I is moved to the left a suflicient distance to allow the ports J to come into register with the ports M. This movement of the valve toward the left closes the ports M. Therefore, during the remainder of the return or compression stroke, and up to the time the piston again covers the exhaust ports in the cylinder, the exhaust is being effected through chamber L to the low pressure exhaust. a

Fig. 5 is a longitudinal cross-sectional view of part of the unaflow cylinder showing exhaust ports in cylinder walls, exhaust belt, and the valves A and .E as shown in Fig. 1.

Fig. 6 shows a slightly modified form of my invention, wherein chamber N is in communication with the high pressure exhaust, and the chamber 0 is in communication with the low pressure exhaust. The clapper valve P is opened by the pressure of the exhaust steam exhausting into the exhaust belt of the cylinder as soon as the piston uncovers the exhaust ports. It will remain open as long as the pressure in the exhaust belt is greater than that in the chamber N, or until the valve Q is open to allow the residual exhaust steam to be exhausted into chamber 0 connected to low pressure system. Therefore, as soon as the pressure in the exhaust belt becomes less than the pressure in the high pressure exhaust chamber N, the valve P will close, either by gravity or by spring or other suitable means. The valve Q, may be operated from a gear attached to a moving part of the engine, or automatically, as desired.

I claim:

1. A unafiow engine cylinder having an exhaust chamber wit-l1 separate outlets, and a piston-controlled port leading to said chamber, and means for selectively controlling said outlets to permit exhaust through said outlets at different times, from said chamber.

2. A unaflow engine cylinder having a piston-controlled exhaust port and separate passages communicating with said port, and means to selectively connect said port with said passages respectively.

3. In a steam engine, in combination, a cylinder having an exhaust port, a piston controlling said port, separate passages communicating with said port, and valves between said port and passages, operative to connect said port with any one of said passages.

t. In a steam engine, in combination, a cylinder having an exhaust chamber and a port opening into the same, a piston controlling said port, high and low pressure exhaust passages connected to said chamber,

and a valve controlling each passage, and operative to permlt flow from the chamber to I said passage.

5. In a steam engine, in combination, a cylinder having an exhaust port, a piston controlling said port, separate passages communicating with said port, a valve controlling each passage, and means to open said valves at different times.

6. In a steam engine, in combination, a cylinder having an exhaust port, a piston controlling said port, high and low pressure passages communicating with said port, a valve controlling each passage, means to open the valve in the high pressure passa e during the ending of the expansion stro e of the piston, and means to open the valve in the low pressure passage during the beginning of the return stroke.

7. An engine cylinder of the continuous flow type, having a piston-controlled exhaust port, and valve controlled passages leading from said port and communicating with exhausts of different pressures.

8. An engine cylinder of the unafiow type having exhaust passages communicating with the cylinder at the same point in the length thereof, a piston controlling the flow to the same, valves controlling the flow through said passages, and means to selectively operate the valves.

In testimony whereof, I afiix my signature in presence of two witnesses.

EDWIN H. LUDEMAN.

Witnesses:

R. B. TEW', GEO. E. TEW.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. 0. 

